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Piezoelectric‐Effect‐Enhanced Full‐Spectrum Photoelectrocatalysis in p–n Heterojunction
Author(s) -
Liu Zhirong,
Wang Longwei,
Yu Xin,
Zhang Jian,
Yang Ruiqi,
Zhang Xiaodi,
Ji Yanchen,
Wu Mengqi,
Deng Lin,
Li Linlin,
Wang Zhong Lin
Publication year - 2019
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201807279
Subject(s) - materials science , nanorod , photocurrent , heterojunction , optoelectronics , piezoelectricity , visible spectrum , titanium dioxide , semiconductor , barium titanate , band gap , perovskite (structure) , nanotechnology , chemical engineering , dielectric , composite material , engineering
Photoelectrochemical (PEC) water splitting offers a promising strategy for converting solar energy to chemical fuels. Herein, a piezoelectric‐effect–enhanced full‐spectrum photoelectrocatalysis with multilayered coaxial titanium dioxide/barium titanate/silver oxide (TiO 2 /BTO/Ag 2 O) nanorod array as the photoanode is reported. The vertically grown nanorods ensure good electron conductivity, which enables fast transport of the photogenerated electrons. Significantly, the insertion of a piezoelectric BaTiO 3 (BTO) nanolayer at the p‐type Ag 2 O and n‐type TiO 2 interface created a polar charge‐stabilized electrical field. It maintains a sustainable driving force that attract the holes of TiO 2 and the electrons of Ag 2 O, resulting in greatly increased separation and inhibited recombination of the photogenerated carriers. Furthermore, Ag 2 O as a narrow bandgap semiconductor has a high ultraviolet–visible–near infrared (UV–vis–NIR) photoelectrocatalytic activity. The TiO 2 /BTO/Ag 2 O, after poling, successfully achieves a prominent photocurrent density, as high as 1.8 mA cm −2 at 0.8 V versus Ag/Cl, which is about 2.6 times the TiO 2 nanorod photoanode. It is the first time that piezoelectric BaTiO 3 is used for tuning the interface of p‐type and n‐type photoelectrocatalyst. With the enhanced light harvesting, efficient photogenerated electron–hole pairs' separation, and rapid charge transfer at the photoanode, an excellent photoelectrocatalytic activity is realized.